JPS63181644A - Cooler for rotor of sealed motor - Google Patents

Abstract

PURPOSE:To obtain effective cooling effect, by a method wherein cut-out work except the penetrating holes of secondary coil grooves and a rotor shaft is applied on a part of the iron sheets of a laminated core, constituting a rotor, a part of the cut-out works is overlapped mutually and cooling grooves are constituted in the rotor from the axial center thereof along the inner periphery of the rotor. CONSTITUTION:In a sealed motor 2, integrated with a sealed compressor 1, cut-out work except penetrating holes for the inserting grooves of a secondary coil conductor and a rotary shaft 5 is applied on a part of iron core sheets of a laminated core, constituting a rotor 4, and a part of the cut-out work is overlapped to form cooling grooves in the rotor 4 from the axial center thereof along the inner periphery of the rotor. The core sheet of the laminated core, constituting the rotor for example, is constituted of base iron sheets (a) having the penetrating holes for the rotary shaft 5 and the inserting grooves for the secondary coil conductor and iron sheets (b)-(f), which are made by applying the cut-out work on the iron sheet (a). Thereafter, the iron sheets (a)-(f) are superposed whereby cooling grooves 12, 14, 15 may be constituted.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cooling device for a rotor of a sealed electric motor, and is configured to obtain an effective cooling effect on the rotor using a cooling liquid.

Here, a sealed electric motor is one that is sealed with a frame that covers the rotor and a bracket that holds the bearing. It refers to a can-type electric motor that is sealed with a bracket or the like, and its load is generally intended for gas compressors.

Generally, it is no exaggeration to say that the output capacity of a motor is limited by the temperature rise caused by motor loss, and cooling to remove the generated heat is important, especially in the case of a sealed type. This generated heat can be roughly classified into the stator side and the rotor side, and in general-purpose machines, both are cooled by a cooling fan attached to the rotor, but this is not the case with sealed types. It is possible. Therefore, on the stator side, heat is radiated from the frame and bracket, but on the rotor side, heat is radiated through the atmosphere surrounding the rotor.
The latter is better, but the rotor rotates in a coolant, or the coolant is spread inside the stator. Therefore, it cannot be said that it is necessarily satisfactory in terms of structure and performance.

The present invention has been made in view of these points.

Fig. 1 (a) is a schematic diagram of a box-type electric motor as an example of a sealed electric motor. Machine, 2 is a sealed electric motor connected to this, and both 1,
2 are connected by a through hole 3, but are completely isolated from the atmosphere and have a sealed structure, and the shaft sealing device of the compressor 1 is removed, so there is no need for it. 4 is a rotor for driving the compressor, and 5 is a rotor shaft, which is directly connected to the compressor.

In this figure, the bearing part is cantilevered. 6 is a stator around which the stator wire is wound, 7 is a coolant supply port drilled in the rotating shaft 5, and 8 is a liquid supply pipe, which also serves as bearing lubrication and supplies lubricating oil as a coolant. Supplied.

(+:+) In the figure, 9 is a secondary wire ring conductor inserted into a wire groove drilled in the rotor core 4, and is arranged on the inner periphery of the stator core, both ends of which are connected to the short-circuit ring 1o. It has a boxy shape. Reference numeral 11 indicates a coolant core discharge port, and 12 indicates a core cooling groove for the coolant along the inner circumference of the rotor.

FIG. 2(a) is an example of a core plate of a part of the laminated core constituting the rotor 4, and each of the core plates (a) to (f) has undergone various cutting processes. (a) is a basic type of iron plate laminated on both sides and the middle part of the rotor, and only has a secondary raceway groove and a rotating shaft through hole.

(b) to (f) are basic iron plates with other cutouts, of which (b) has cutouts that form radial cooling grooves 14 extending from the rotor through hole toward the outer periphery. (C) is a core plate with circular arc-shaped cooling grooves 15, which is a basic iron core plate that has been cut out in symmetrical positions, (d) and (
,) are exactly the same as (c), (b) is drawn by rotating the iron plate by 6C3, and (f) is exactly the same as (b). These (1), (b), (C) (a) l (e) l (
f) l If (a) are overlapped, the grooves will communicate with each other at the overlapped portion, and (b) the core plate radial cooling grooves 14
The rotor 4 is assembled by stacking the (f) iron core plates in alignment with the coolant core discharge port 12 of the rotating shaft and the coolant core discharge port 13. By doing this, (b) to (f)
This means that the lightning-type cooling grooves 12 can be constructed in the rotor core using the iron plate. The cross section of the cooling groove in the electric core can be arbitrarily selected according to each of the steel plate thicknesses shown in (b) to (f), or by repeating K of the above arrangement, the rotor core can span the total thickness of y. This means that the cooling grooves can be easily configured in series or in parallel.

Figure 2 (b) is 1800 around X-X- in Figure 1←)
This is a developed view of the rotor, showing the lightning-type cooling grooves 12 arranged in parallel.

The cutout shape of each steel plate that makes up the cooling groove is the simplest circular cutout, and the plates can be layered overlapping each other to form the cooling groove, and are not limited to the shape of the cutout. .

In the figure, the lubricating oil that becomes the cooling liquid is released from the shaft end inside the stator, led outside, and circulated through an external heat exchanger, lubricating oil tank, etc., but these parts are omitted. do. There are no limitations to the refrigerant liquid either.

Since the core plate with such cutouts is meticulously symmetrical, the constructed rotor is statically and dynamically balanced with respect to the rotor axis, and the core shape is There is no vibration caused by unbalance.

As described above, in the present invention, cooling in the case of a sealed electric motor, especially cooling the rotor, is important.When a compressor is used as a cooling device and the refrigerant is fluorocarbon, the maximum temperature is 130°C. It is said that the temperature is limited to about 0.degree. C., and that thermal decomposition will occur if the temperature exceeds 5 degrees Celsius, so it is possible to adequately deal with such cases.

In addition, the design of the cooling groove is extremely easy, the structure is simple, there is no vibration caused by rotor imbalance, and it is possible to provide an excellent cooling device for the rotor of a sealed motor. It is possible.

[Brief explanation of the drawings] Figure 1 is a schematic diagram of a sealed electric motor integrated with a compressor, P) is a partial sectional view, and P is a schematic diagram of the rotor and its Y
-Y' cross-sectional view, the marks in Figure 2 indicate the various shapes of the iron core plates that make up the rotor, (b)
is a developed view of the rotor. 1: sealed compressor, 2: sealed electric motor, 4: rotor 5; rotor shaft, 7: coolant supply port, 8; liquid supply pipe,
11; Coolant in-core discharge port, 12; Core cooling groove, 13
; Coolant core self-discharge port, 14: Radial cooling groove, 15
; Arc-shaped cooling groove. Applicant Maekawa Manufacturing Co., Ltd.

Claims (1)

[Claims] (1) A part of the core plate of the laminated core constituting the rotor is cut out other than the secondary side wire ring groove and the through hole of the rotor shaft, and a part of these cutouts are overlapped with each other, 1. A cooling device for a rotor of a sealed motor, characterized in that a cooling groove is formed inside the rotor of the sealed motor, extending from the shaft center to the inner circumference of the rotor.